Comments

I am not a mother tongue, but I would just use The Valdez in this case. The article is enough for me to make explicit that they are two or more. If it was only one you would have said just Valdez, isn't it?

But, as I said, i am not mother tongue... don't count on me saying the right thing...

Oh, silly us, AO. The possessive really should be "the Valdezes' ", shouldn't it? "The Valdez' " or "the Valdez's" only makes sense if there's only one of them. In that case, there would be no "the" unless he or she is THE Valdez, the one and only, the greatest Valdez ever!

probably plural is Valdezes, although it's not exactly set in stone, seeing as it's a non-english word. What's happening is that you're applying a fairly general english rule to a close-enough case and english is flexible enough for that to be acceptable. However, you should note that it is technically correct to use an apostrophe for "hard to pluralize cases", notably P's and Q's, so if you had a violent objection to integrating a spanish word into a spanish-english hybrid plural, then an argument can be made that Valdez's is correct (or at least not incorrect, if you're taking Who Wants to be a Millionaire to court after getting the final question wrong).

style guides generally suggest writing the possessive s where it is pronounced, so possessive Valdez's rather than Valdez' for the singular, but really it's optional

Why not just refer to those names as a group unit? Such as "the Valdez Family". Maybe even "the Valdez household" in case of a unknown marial status. Seems like that would be the easiest way to git 'er done. :)

The "ending with an apostrophe" rule only applies for the letter "s" (not z, x, sh, etc.), and only in certain situations: Jesus', Moses' and words in which the possessive "s" is not pronounced (boys', girls').

"Chris's" is pronounced so "Chrisses", it should end with apostrophe-s.

Valdez ends with z, and it's pronounced "Valdezzes" anyway, so it ends with 's.

When speaking English and saying plural of a Spanish surname, the name gets said the same as the singular.

An right-speaking English speaker says "Juan Valdez", "Juan and Juanita Valdez" and "The Valdez".

When speaking Spanish and saying plural of a Spanish surname, the name gets said the same as the singular. However, the singular masculine or feminine definitive article, depending upon the name, article gets changed to the plural definitive article.

When speaking Spanish and saying plural of a Spanish surname, the name gets said the same as the singular. However, the singular masculine or feminine definitive article, depending upon the name, article gets changed to the plural definitive article.

When speaking Spanish and saying the plural form of a Spanish surname, the name gets said the same as the singular form. However, the singular masculine or feminine definitive article, depending upon the name, gets changed to the plural definitive article.

To answer Ann's question, the plural of Marschuetz is Marschuetzes. The ornament should read: "Love, the Marschuetzes." (Don't capitalize the article "the," it isn't an honorific.)

As for the original question, those who have argued that a name of non-English origin should be made possessive in the manner of the language of origin are incorrect. It is, in fact, impossible in some cases. For example, Mandarin does not alter the name to make it possessive, instead it uses the particle "de" to indicate possession:

Zhe shi Mao xian sheng de ge ge.

This is Mr. Mao's elder brother.

To apply the Mandarin practice to English would be awkward, and limiting: "This is the elder brother of Mr. Mao."

The same holds true for plurals of proper names, which are treated by English rules regardless of origin. And the rule is simple, at least as English rules go. Most names simply add '-s', while those ending in 's', 'x', or 'z', or in a sibilant 'ch' or 'sh' add '-es'.

@Larkin - I second Hairy Scot - I don't see any reason why surnames should be any different from other nouns - brooch / brooches, church / churches, Goodrich / Goodriches - as in this book - The Goodriches: An American Family